1 files changed, 302 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-hlwd.c b/drivers/gpio/gpio-hlwd.c
new file mode 100644
index 000000000..4e13e937f
--- /dev/null
+++ b/drivers/gpio/gpio-hlwd.c
@@ -0,0 +1,302 @@
+// SPDX-License-Identifier: GPL-2.0+
+// Copyright (C) 2008-2009 The GameCube Linux Team
+// Copyright (C) 2008,2009 Albert Herranz
+// Copyright (C) 2017-2018 Jonathan Neuschäfer
+//
+// Nintendo Wii (Hollywood) GPIO driver
+
+#include <linux/gpio/driver.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/slab.h>
+
+/*
+ * Register names and offsets courtesy of WiiBrew:
+ * https://wiibrew.org/wiki/Hardware/Hollywood_GPIOs
+ *
+ * Note that for most registers, there are two versions:
+ * - HW_GPIOB_* Is always accessible by the Broadway PowerPC core, but does
+ *   always give access to all GPIO lines
+ * - HW_GPIO_* Is only accessible by the Broadway PowerPC code if the memory
+ *   firewall (AHBPROT) in the Hollywood chipset has been configured to allow
+ *   such access.
+ *
+ * The ownership of each GPIO line can be configured in the HW_GPIO_OWNER
+ * register: A one bit configures the line for access via the HW_GPIOB_*
+ * registers, a zero bit indicates access via HW_GPIO_*. This driver uses
+ * HW_GPIOB_*.
+ */
+#define HW_GPIOB_OUT		0x00
+#define HW_GPIOB_DIR		0x04
+#define HW_GPIOB_IN		0x08
+#define HW_GPIOB_INTLVL		0x0c
+#define HW_GPIOB_INTFLAG	0x10
+#define HW_GPIOB_INTMASK	0x14
+#define HW_GPIOB_INMIR		0x18
+#define HW_GPIO_ENABLE		0x1c
+#define HW_GPIO_OUT		0x20
+#define HW_GPIO_DIR		0x24
+#define HW_GPIO_IN		0x28
+#define HW_GPIO_INTLVL		0x2c
+#define HW_GPIO_INTFLAG		0x30
+#define HW_GPIO_INTMASK		0x34
+#define HW_GPIO_INMIR		0x38
+#define HW_GPIO_OWNER		0x3c
+
+struct hlwd_gpio {
+	struct gpio_chip gpioc;
+	struct irq_chip irqc;
+	void __iomem *regs;
+	int irq;
+	u32 edge_emulation;
+	u32 rising_edge, falling_edge;
+};
+
+static void hlwd_gpio_irqhandler(struct irq_desc *desc)
+{
+	struct hlwd_gpio *hlwd =
+		gpiochip_get_data(irq_desc_get_handler_data(desc));
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	unsigned long flags;
+	unsigned long pending;
+	int hwirq;
+	u32 emulated_pending;
+
+	raw_spin_lock_irqsave(&hlwd->gpioc.bgpio_lock, flags);
+	pending = ioread32be(hlwd->regs + HW_GPIOB_INTFLAG);
+	pending &= ioread32be(hlwd->regs + HW_GPIOB_INTMASK);
+
+	/* Treat interrupts due to edge trigger emulation separately */
+	emulated_pending = hlwd->edge_emulation & pending;
+	pending &= ~emulated_pending;
+	if (emulated_pending) {
+		u32 level, rising, falling;
+
+		level = ioread32be(hlwd->regs + HW_GPIOB_INTLVL);
+		rising = level & emulated_pending;
+		falling = ~level & emulated_pending;
+
+		/* Invert the levels */
+		iowrite32be(level ^ emulated_pending,
+			    hlwd->regs + HW_GPIOB_INTLVL);
+
+		/* Ack all emulated-edge interrupts */
+		iowrite32be(emulated_pending, hlwd->regs + HW_GPIOB_INTFLAG);
+
+		/* Signal interrupts only on the correct edge */
+		rising &= hlwd->rising_edge;
+		falling &= hlwd->falling_edge;
+
+		/* Mark emulated interrupts as pending */
+		pending |= rising | falling;
+	}
+	raw_spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags);
+
+	chained_irq_enter(chip, desc);
+
+	for_each_set_bit(hwirq, &pending, 32)
+		generic_handle_domain_irq(hlwd->gpioc.irq.domain, hwirq);
+
+	chained_irq_exit(chip, desc);
+}
+
+static void hlwd_gpio_irq_ack(struct irq_data *data)
+{
+	struct hlwd_gpio *hlwd =
+		gpiochip_get_data(irq_data_get_irq_chip_data(data));
+
+	iowrite32be(BIT(data->hwirq), hlwd->regs + HW_GPIOB_INTFLAG);
+}
+
+static void hlwd_gpio_irq_mask(struct irq_data *data)
+{
+	struct hlwd_gpio *hlwd =
+		gpiochip_get_data(irq_data_get_irq_chip_data(data));
+	unsigned long flags;
+	u32 mask;
+
+	raw_spin_lock_irqsave(&hlwd->gpioc.bgpio_lock, flags);
+	mask = ioread32be(hlwd->regs + HW_GPIOB_INTMASK);
+	mask &= ~BIT(data->hwirq);
+	iowrite32be(mask, hlwd->regs + HW_GPIOB_INTMASK);
+	raw_spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags);
+}
+
+static void hlwd_gpio_irq_unmask(struct irq_data *data)
+{
+	struct hlwd_gpio *hlwd =
+		gpiochip_get_data(irq_data_get_irq_chip_data(data));
+	unsigned long flags;
+	u32 mask;
+
+	raw_spin_lock_irqsave(&hlwd->gpioc.bgpio_lock, flags);
+	mask = ioread32be(hlwd->regs + HW_GPIOB_INTMASK);
+	mask |= BIT(data->hwirq);
+	iowrite32be(mask, hlwd->regs + HW_GPIOB_INTMASK);
+	raw_spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags);
+}
+
+static void hlwd_gpio_irq_enable(struct irq_data *data)
+{
+	hlwd_gpio_irq_ack(data);
+	hlwd_gpio_irq_unmask(data);
+}
+
+static void hlwd_gpio_irq_setup_emulation(struct hlwd_gpio *hlwd, int hwirq,
+					  unsigned int flow_type)
+{
+	u32 level, state;
+
+	/* Set the trigger level to the inactive level */
+	level = ioread32be(hlwd->regs + HW_GPIOB_INTLVL);
+	state = ioread32be(hlwd->regs + HW_GPIOB_IN) & BIT(hwirq);
+	level &= ~BIT(hwirq);
+	level |= state ^ BIT(hwirq);
+	iowrite32be(level, hlwd->regs + HW_GPIOB_INTLVL);
+
+	hlwd->edge_emulation |= BIT(hwirq);
+	hlwd->rising_edge &= ~BIT(hwirq);
+	hlwd->falling_edge &= ~BIT(hwirq);
+	if (flow_type & IRQ_TYPE_EDGE_RISING)
+		hlwd->rising_edge |= BIT(hwirq);
+	if (flow_type & IRQ_TYPE_EDGE_FALLING)
+		hlwd->falling_edge |= BIT(hwirq);
+}
+
+static int hlwd_gpio_irq_set_type(struct irq_data *data, unsigned int flow_type)
+{
+	struct hlwd_gpio *hlwd =
+		gpiochip_get_data(irq_data_get_irq_chip_data(data));
+	unsigned long flags;
+	u32 level;
+
+	raw_spin_lock_irqsave(&hlwd->gpioc.bgpio_lock, flags);
+
+	hlwd->edge_emulation &= ~BIT(data->hwirq);
+
+	switch (flow_type) {
+	case IRQ_TYPE_LEVEL_HIGH:
+		level = ioread32be(hlwd->regs + HW_GPIOB_INTLVL);
+		level |= BIT(data->hwirq);
+		iowrite32be(level, hlwd->regs + HW_GPIOB_INTLVL);
+		break;
+	case IRQ_TYPE_LEVEL_LOW:
+		level = ioread32be(hlwd->regs + HW_GPIOB_INTLVL);
+		level &= ~BIT(data->hwirq);
+		iowrite32be(level, hlwd->regs + HW_GPIOB_INTLVL);
+		break;
+	case IRQ_TYPE_EDGE_RISING:
+	case IRQ_TYPE_EDGE_FALLING:
+	case IRQ_TYPE_EDGE_BOTH:
+		hlwd_gpio_irq_setup_emulation(hlwd, data->hwirq, flow_type);
+		break;
+	default:
+		raw_spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags);
+		return -EINVAL;
+	}
+
+	raw_spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags);
+	return 0;
+}
+
+static int hlwd_gpio_probe(struct platform_device *pdev)
+{
+	struct hlwd_gpio *hlwd;
+	u32 ngpios;
+	int res;
+
+	hlwd = devm_kzalloc(&pdev->dev, sizeof(*hlwd), GFP_KERNEL);
+	if (!hlwd)
+		return -ENOMEM;
+
+	hlwd->regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(hlwd->regs))
+		return PTR_ERR(hlwd->regs);
+
+	/*
+	 * Claim all GPIOs using the OWNER register. This will not work on
+	 * systems where the AHBPROT memory firewall hasn't been configured to
+	 * permit PPC access to HW_GPIO_*.
+	 *
+	 * Note that this has to happen before bgpio_init reads the
+	 * HW_GPIOB_OUT and HW_GPIOB_DIR, because otherwise it reads the wrong
+	 * values.
+	 */
+	iowrite32be(0xffffffff, hlwd->regs + HW_GPIO_OWNER);
+
+	res = bgpio_init(&hlwd->gpioc, &pdev->dev, 4,
+			hlwd->regs + HW_GPIOB_IN, hlwd->regs + HW_GPIOB_OUT,
+			NULL, hlwd->regs + HW_GPIOB_DIR, NULL,
+			BGPIOF_BIG_ENDIAN_BYTE_ORDER);
+	if (res < 0) {
+		dev_warn(&pdev->dev, "bgpio_init failed: %d\n", res);
+		return res;
+	}
+
+	res = of_property_read_u32(pdev->dev.of_node, "ngpios", &ngpios);
+	if (res)
+		ngpios = 32;
+	hlwd->gpioc.ngpio = ngpios;
+
+	/* Mask and ack all interrupts */
+	iowrite32be(0, hlwd->regs + HW_GPIOB_INTMASK);
+	iowrite32be(0xffffffff, hlwd->regs + HW_GPIOB_INTFLAG);
+
+	/*
+	 * If this GPIO controller is not marked as an interrupt controller in
+	 * the DT, skip interrupt support.
+	 */
+	if (of_property_read_bool(pdev->dev.of_node, "interrupt-controller")) {
+		struct gpio_irq_chip *girq;
+
+		hlwd->irq = platform_get_irq(pdev, 0);
+		if (hlwd->irq < 0) {
+			dev_info(&pdev->dev, "platform_get_irq returned %d\n",
+				 hlwd->irq);
+			return hlwd->irq;
+		}
+
+		hlwd->irqc.name = dev_name(&pdev->dev);
+		hlwd->irqc.irq_mask = hlwd_gpio_irq_mask;
+		hlwd->irqc.irq_unmask = hlwd_gpio_irq_unmask;
+		hlwd->irqc.irq_enable = hlwd_gpio_irq_enable;
+		hlwd->irqc.irq_set_type = hlwd_gpio_irq_set_type;
+
+		girq = &hlwd->gpioc.irq;
+		girq->chip = &hlwd->irqc;
+		girq->parent_handler = hlwd_gpio_irqhandler;
+		girq->num_parents = 1;
+		girq->parents = devm_kcalloc(&pdev->dev, 1,
+					     sizeof(*girq->parents),
+					     GFP_KERNEL);
+		if (!girq->parents)
+			return -ENOMEM;
+		girq->parents[0] = hlwd->irq;
+		girq->default_type = IRQ_TYPE_NONE;
+		girq->handler = handle_level_irq;
+	}
+
+	return devm_gpiochip_add_data(&pdev->dev, &hlwd->gpioc, hlwd);
+}
+
+static const struct of_device_id hlwd_gpio_match[] = {
+	{ .compatible = "nintendo,hollywood-gpio", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, hlwd_gpio_match);
+
+static struct platform_driver hlwd_gpio_driver = {
+	.driver	= {
+		.name		= "gpio-hlwd",
+		.of_match_table	= hlwd_gpio_match,
+	},
+	.probe	= hlwd_gpio_probe,
+};
+module_platform_driver(hlwd_gpio_driver);
+
+MODULE_AUTHOR("Jonathan Neuschäfer <j.neuschaefer@gmx.net>");
+MODULE_DESCRIPTION("Nintendo Wii GPIO driver");
+MODULE_LICENSE("GPL");